West Branch Susquehanna River at Allenwood

Highest listed crest 26.07 ftFlood stage 24.0 ft8 crests since 2015

The West Branch Susquehanna River at Allenwood crested above flood stage 3 times among the 8 crests the National Weather Service lists from 2015 to 2024. The highest, 26.07 ft on September 11, 2018, was moderate flooding, 2.07 feet above flood stage. 6 other gauges on the West Branch Susquehanna River crested above flood stage within a week of it.

The gauge

Highest listed crest: 26.07 ft; September 11, 2018; 45,500 cubic feet per second
Flood stage: 24.0 ft; Major flooding from 30.0 ft
Crests at major: 0; 3 above flood stage
Most recent flood crest: August 10, 2024; 24.75 ft, minor flooding
Location: Northumberland County; Near Williamsport (11.9 mi)
Identifiers: NWS ALWP1; USGS 01553025

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, West Branch Susquehanna River at Allenwood

Action stage	20.0	2	May 1, 2020	The level at which the NWS or its partners begin to take action
Flood stage (minor)	24.0	2	Aug 10, 2024	Minimal or no property damage, but possibly some public threat
Moderate flood stage	26.0	1	Sep 11, 2018	Some inundation of structures and roads near the stream
Major flood stage	30.0	0	—	Extensive inundation of structures and roads

Every listed crest

8 crests from 2015 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Crests at or above flood stage, by decade

These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, West Branch Susquehanna River at Allenwood

1	Sep 11, 2018	26.07	+2.07	Moderate	45,500
2	Aug 10, 2024	24.75	+0.75	Minor	105,583
3	Apr 4, 2024	24.10	+0.10	Minor	100,288
4	May 1, 2020	21.35	−2.65	Action	78,900
5	Dec 22, 2018	20.40	−3.60	Action	71,900
6	May 7, 2017	19.15	−4.85	Below flood stage	66,400
7	Feb 25, 2016	16.29	−7.71	Below flood stage	45,500
8	Jul 11, 2015	12.19	−11.81	Below flood stage	21,300

The worst floods along the West Branch Susquehanna River

For this gauge's highest crests, the other gauges on the West Branch Susquehanna River that crested above flood stage within a week.

September 11, 2018: 26.07 ft here, moderate flooding

WilliamsportPA · Sep 11, 2018 · 21.08 ft · Moderate
Lock HavenPA · Sep 11, 2018 · 21.93 ft · Minor
MuncyPA · Sep 11, 2018 · 21.20 ft · Minor
West MiltonPA · Sep 12, 2018 · 20.54 ft · Minor
LewisburgPA · Sep 12, 2018 · 19.35 ft · Minor
RenovoPA · Sep 11, 2018 · 16.11 ft · Minor

August 10, 2024: 24.75 ft here, minor flooding

West MiltonPA · Aug 10, 2024 · 19.08 ft · Minor

Gauges on the West Branch Susquehanna River

Flood gauges sharing the river's name, linked within 80 miles of one another.

Flood gauges on the West Branch Susquehanna River

Allenwood this gauge	PA	24.0	26.07 ft, Sep 11, 2018	0
Jersey Shore	PA	26.0	38.20 ft, Jun 23, 1972	7
Lewisburg	PA	18.0	34.23 ft, Jun 24, 1972	2
Lock Haven	PA	21.0	28.13 ft, Sep 18, 2004	2
Renovo	PA	16.0	29.39 ft, Mar 18, 1936	4
West Milton	PA	19.0	34.55 ft, Jun 24, 1972	12
Williamsport	PA	20.0	34.75 ft, Jun 23, 1972	4
Muncy	PA	20.0	37.45 ft, Jun 23, 1972	8

Other gauges in Northumberland County

Flood gauges in Northumberland County

Lewisburg	18.0	34.23 ft, Jun 24, 1972	2

Northumberland County: every hazard · River floods across the country · Pennsylvania

NOAA National Water Prediction Service, gauge ALWP1, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.